Do you want to learn how to fix a constantly running toilet?
As a home inspector, I frequently get asked by clients about constantly running toilets. A continuously (or randomly) running toilet can potentially waste hundreds of gallons of water per day, spiking your water bill.
In this guide, we’ll go over:
- The top 6 causes (and fixes) of a constantly running toilet
- Step-by-step breakdowns of how to repair it
- How toilets work related to running toilets
- Pictures showing the toilet parts
Let’s get started!
Way #1: Install a New Flapper
The toilet flapper is the rubber or silicone part of the toilet that opens and closes water flow from the tank into the toilet bowl.
Since it is typically made out of rubber or a flexible silicone, it is vulnerable to deterioration over time.
Chlorine in the water, tank cleaning tablets, hard mineral buildup, and just age can cause the flapper to crack or warp allowing water to leak into the toilet bowl.
When water leaks into the bowl, it triggers the fill valve to turn on as the water drops in the tank — leading to a running noise even when the toilet isn’t in use.
A simple dye test can also be done to confirm that the flapper is broken or poorly sealed. Just put a few drops of food dye into the tank and see if the dye leaks into the toilet bowl.
5 Steps To Replace a Flapper
- Buy The Right Size: It’s essential to buy the right sized flapper if you need to replace it. Older toilets usually have a 2 inch wide flapper while newer toilets are typically sized at 3 inches. Ideally, you want to find the exact same replacement flapper by taking a picture of it or looking up the part number if visible on the flapper.
- Turn Off the Water: Shut off the water supply valve to the toilet and then flush it to drain all the water. The handle on the supply line typically needs to be turned clockwise or perpendicular to the water line. For push-fit valves, the handle will need to be pushed inwards.
- Remove Old Flapper: Disconnect the old flapper at the chain. There is typically a simple metal clip that needs to be pulled off the flush lever.
- Install New Flapper: Install the new flapper by connecting the chain to the flush lever. Make sure that the valve seat (receiver) is clean and that it seals well. Allow 1/2 inch of slack in the chain when it’s in the closed position.
- Flush Toilet and Test: Flush the toilet to see if it’s working. You can also perform a food dye test in the tank to see if it is properly sealed.
Way #2: Adjust The Float
An improperly adjusted float is a common way that a toilet keeps running when not in use.
The float is an air-filled part of the flush mechanism that rises as water fills in the tank.
As the float rises, it triggers the fill valve to stop allowing water into the toilet tank.
If the float is not adjusted properly, water will keep rising in the tank until it pours into the overflow tube (the vertical open tube) and pushes water into the toilet.
And as the water level in the toilet tank lowers, it triggers the fill valve to allow more water into the tank — repeating the fill cycle.
The easiest way to verify this is to remove the tank lid, and flush the toilet. Watch the water level as it rises in the tank and to see if it starts pouring into the overflow tube.
Read Also >> How To Unclog A Toilet (Different Methods)
4 Steps To Adjusting a Float
- Check Water Level: Remove tank lid, flush toilet, and watch as the water rises. If water spills into the overflow tube, then the float needs adjustment.
- Adjust the Float for a Cup-Style: For a modern cup-style float, which is on a vertical rod, there is typically an adjustment screw or a small knob at the top of the fill valve. Turn the screw or knob clockwise to lower the float.
- Adjust The Float For Ball-Style: For older ball-style floats, you will need to bend the metal arm downward or turn the adjustment screw counterclockwise.
- Test By Flushing Toilet: Flush the toilet and watch as the water rises. The water should stop about 1 inch below the top of the overflow tube.
Way #3: Adjust The Flapper Chain
The flapper chain connects the flapper to the flush handle.
If the chain is too long it can get caught underneath the flapper leading to a constantly running toilet.
An overly long chain can also get tangled or twisted which may accidentally shorten the chain causing a poor flapper seal.
And if the chain is too short, the flapper won’t close properly allowing water into the toilet bowl.
The easiest way to verify the working of the flapper chain is to remove the tank lid and flush the toilet. Carefully look at the flapper chain (and the flapper) to see if it is too short or too long.
The flapper chain should only have about a 1/2 inch play when the flush handle is not pressed down.
4 Steps To Adjusting the Flapper Chain
- Inspect The Chain: Remove the tank lid and flush the toilet. Inspect the chain to see if it is too long or too short causing an improperly sealed flapper. If the chain is too long, it may only sometimes cause problems by getting stuck underneath the flapper.
- Turn Off Water To Toilet: Locate the water supply valve to the toilet and shut off the valve. The water supply handle usually needs to either be turned clockwise or perpendicular to the supply hose. For push-fit valves, the handle will need to be pushed inwards.
- Adjust The Chain: Unhook the top part of the chain from the connecting link and move it to a higher or lower link. You want about 1/2 inch slack in the chain when the flush handle isn’t pressed down.
- Test The Adjustment: Turn the water supply back on to the toilet and flush the toilet. Verify that the flapper gets sealed completely when it goes back down.
Read Also >> What Are Common Toilet Building Codes?
Way #4: Replace Faulty Fill Valve
The fill valve is an essential part of the toilet because it precisely fills the tank after each flush and shuts off the water when the correct level is reached.
Sometimes the fill valve just needs replacement either due to a crack or hole which leads to a randomly or continuously running toilet.
For old fill valves, they sometimes develop worn seals or mineral deposit clogs that lead to random or inconsistent water tank fills.
A few signs of a malfunctioning fill valve include a trickling sound, hissing sound, inconsistent tank fills, or water that continuously pours into the overflow tube.
If you inspected or changed the flapper and flapper chain, you may need to just change out the fill valve.
7 Steps To Replacing a Fill Valve
- Turn Off Water: Shut off water to the toilet by turning the supply valve either clockwise or perpendicular to the water line. If you have a push-fit valve, the circular handle will need to be pushed inwards.
- Remove Remaining Water: In order to avoid water spilling onto the floor, remove the remaining water in the tank with either a sponge or towel.
- Disconnect Water Supply Line: From underneath the toilet tank, you will need to use an adjustable wrench to disconnect the coupling nut that connects the water line to the bottom of the old fill valve. Turn the nut counterclockwise when facing up.
- Remove Old Fill Valve: There may be a second nut inside the tank that will need to be removed, connecting the fill valve to the water line (and the bottom of tank). Turn the plastic nut counterclockwise looking down. Carefully pull out the old fill valve.
- Install New Fill Valve: Insert the new fill valve into the toilet using the provided rubber washers to avoid it from leaking. Turn the provided nuts (inside and outside the tank) clockwise to tighten.
- Connect Water Line: Re-connect the water line to the bottom of the fill valve.
- Make Adjustments: The water should fill to about 1 inch below the top of the overflow tube. Turn the adjustment screw or handle until it fills correctly.
Way #5: Replace Or Clean Overflow Tube
The overflow tube is the open vertical pipe sticking out of the toilet tank that allows water into the toilet bowl.
It is primarily a safety mechanism to prevent the tank water from rising too high and spilling onto the floor.
There is also a small water line that is clipped onto the tube (from the fill valve) to allow the toilet to fill with water after a flush.
Even though it’s rare, if the overflow tube has a small crack or hole below the water line, it can contribute to a constantly running toilet.
Also, mineral deposits can partially clog the overflow tube which leads to weak flushes if the toilet doesn’t fill with enough water after a flush.
Read Also >> Why Toilet Makes Burping & Bubbling Sounds?
8 Steps To Changing An Overflow Tube
- Turn Off Water: Shut off the water supply line to the toilet. Turn the valve perpendicular to the water line, clockwise, or push inwards on a push-fit valve.
- Drain Tank: Flush the toilet to drain the tank water and use a towel or sponge to remove any remaining water.
- Disconnect Flapper Chain And Refill Tubing: Unhook the chain from the flapper and disconnect the small water line that goes into the overflow tube.
- Remove The Tank If Needed: For most toilets, you will need to remove the tank from the toilet since the overflow tube is part of the flush valve (flapper) and is secured to the bottom of the tank. Use a wrench to remove the tank bolts and carefully lift the tank and put it on a towel.
- Unfasten Old Overflow Tube: Use channel-lock pliers or a large adjustable wrench to loosen the large nut underneath the overflow tube at bottom of tank. Lift out the overflow tube and flush valve assembly from the tank.
- Install New Overflow Tube: Install the new overflow tube and tighten the large nut.
- Install the Tank: Reverse the steps and re-install the toilet tank.
- Turn On Water and Test: Slowly turn on the water and allow the tank to fill. Flush the toilet and check for any leaks.
Way #6: Tighten Or Replace Flush Handle
A loose or faulty flush handle can partially keep the flapper open or improperly sealed leading to a constantly running toilet.
If the flush handle is too loose, it may not fully return after flushing, keeping the chain tight and raising the flapper.
If the flush handle is too tight, it likewise may cause an improper seal of the flapper, leading to a constantly running toilet.
The fix may be as simple as tightening or loosening of the nut on the flush handle or a simple replacement.
Homeowners should remove the tank lid and flush the toilet, inspecting whether the flush handle is operating correctly with the flapper giving a proper seal.
5 Steps To Replacing Flush Handle
- Pull Off Tank Lid: Carefully remove the tank lid and disconnect the chain from the flush handle.
- Remove Handle Nut: Use a wrench to loosen the nut by turning counterclockwise, and pull off nut and handle.
- Install New Handle: Install the new handle by inserting it into hole and turning the nut clockwise by hand.
- Install Chain: Reconnect chain to flush handle, make sure there is a 1/2 inch slack in the chain when unpressed.
- Test: Flush toilet and verify that the flapper seals correctly.
Read Also >> Weird Sounds Toilets Make And How To Fix Them
How Toilets Work Related To A Running Toilet
A constant or randomly running toilet is typically related to the plumbing parts inside the toilet tank which controls flushing and water levels.
When a user presses down on the flush handle [1], it moves the chain [2] which connects to the flapper [3].
The rubber flapper lifts up which allows water to flow into the toilet bowl for a flush.
When the flapper isn’t fully seated due to a poor seal — from the flapper itself or a misaligned chain — it can cause a constantly running toilet.
Once water drops in the tank after a flush, the float [4] of the fill valve [5] drops and turns on water in the tank.
The water in the toilet tank will keep rising until the air-filled float rises which deactivates the fill valve and shuts off the water. A leaking fill valve, however, will constantly release water into the tank, causing it to keep running.
And if the fill valve float adjuster [6] is turned too high, then water will flow into the overflow tube, leading to a continuously running toilet.
The overflow tube [7] itself can also be cracked or improperly positioned which leads to constant water flow.
Final Thoughts
A constantly running toilet is more than just the annoying sound of trickling water.
A toilet that keeps using water can waste around 200 gallons of water per day according to the EPA.
It can also prematurely wear out your toilet’s internal parts and even lead to excess moisture in the bathroom leading to mold problems.
Fortunately, it is usually a simple fix through adjustments or replacing worn out parts. Some common causes are usually a poorly sealed flapper, a faulty fill valve, improper float adjustment, or a faulty handle chain.
After fixing a running toilet, you can have peace of mind that you aren’t wasting water and constantly running your toilet.
Leave a comment below about your toilet problem or ask me a question. I hope you enjoyed this guide by TimberSill!
2 thoughts on “6 Ways To Fix A Running Toilet”
Our toilets run a really long time after each flush. Can it be adjusted to not run so long?
You may just need to adjust the float in the toilet tank to a lower position. There is an adjustment screw in the tank that allows you to lower it. Also, the flapper may be worn or defective and doesn’t seal properly — taking longer for the tank to fill up.